At two and a half years old, Kephart's son, Jeremy, was diagnosed as suffering from pervasive developmental disorder, a condition that has some of the elements of autism. The child's speech was ""atypical,"" he was terrified of contact with everyone but his parents and grandparents, and his life became characterized by certain behaviors that became obsessions. Because his situation was so anomalous, even professionals used to dealing with so-called exceptional children were at a loss as to how to cope with Jeremy at times. But the Pennsylvania-based author and her husband, Bill, after blaming themselves for the child's difficulties and encountering problems with experts, determined to deal with their son on his own terms and to modify his behavior without wrenching him away from his few interests, ranging from trains and cars to planes and trucks, and by letting him set his own pace when encountering other children and adults. They also chose his schools wisely, with the result that Jeremy now functions well in society at age nine. Freelancer Kephart conveys her frantic reaction to the original diagnosis, her furious desire to change conditions for Jeremy at once and her ultimate realization that a tangible, positive outcome was possible, given great patience. Kephart tells an affecting story of parental dedication. (June)